Mostly agree with your views, but the most important thing is to consider the electro-mechano-acoustical (EMA) analogy.
Microphones and loudspeakers consist of coupled mechanical, acoustical and electrical subsystems.
Analysis has to consider all subsystems in an integral way.
As I stated:
You 'could' use an OSWG in '(mass) reactive mode' and push the driver below its comfort zone, but it won't sound particularly nice and you risk frying 'phrams at higher SPL, as Geddes found out when some of his speakers were used in a club.
No, again you're trying to make this about driver excursion.
I'm talking about the waveguide alone used down through the reactive region. No driver limitations. What does it sound like?
I'm talking about the waveguide alone used down through the reactive region. No driver limitations. What does it sound like?
What do you think?
What's the point of considering the waveguide without a driver (= no sound)?
Of course, with a powerful driver, e.g. the Axi2050, an OSWG could also be crossed lower, but still not as low as with a classic horn.
This topic has been flogged to death. Opinions will always differ, perhaps with the exception of the pro audio community.
What's the point of considering the waveguide without a driver (= no sound)?
Of course, with a powerful driver, e.g. the Axi2050, an OSWG could also be crossed lower, but still not as low as with a classic horn.
This topic has been flogged to death. Opinions will always differ, perhaps with the exception of the pro audio community.
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Here's an example of someone who swapped the BMS 4592ND for the Axi2050, actively crossed at 300 Hz, but using the BD-Design Oris horns (150 Hz cutoff).
You could get away with a huge OSWG (40 or 60° included angle) and the same XO, but I doubt it would yield satisfactory results.
You could get away with a huge OSWG (40 or 60° included angle) and the same XO, but I doubt it would yield satisfactory results.
i previously said all modern compression drivers are annual but i take it back
this dome driver is modern:
https://audioxpress.com/article/test-bench-faital-pro-s-new-hf1460-pro-sound-compression-driver-1
and would be a very good choice from about 1.5 khz to 8 khz
you could use a supertweeter and perhaps a 8" paper midrange to complete the setup
this dome driver is modern:
https://audioxpress.com/article/test-bench-faital-pro-s-new-hf1460-pro-sound-compression-driver-1
and would be a very good choice from about 1.5 khz to 8 khz
you could use a supertweeter and perhaps a 8" paper midrange to complete the setup
Troy Crowe designed a large OSWG.
Specification
" The idea is to provide a large format oblate spheroidal horn flare which is characterized as a conical horn with a smooth throat transition.
Design Goals
By moving the mic away to 1m, removing the gate, and applying some smoothing,
we get a better sense on what happens near the cutoff frequency of the horn:
Response at 0,15,30, & 45 degrees off-axis:
Below is the response of the Yuichi A290 with the RCF ND940/950.
Please note that the ND940 is simply the ND950 with the conical adapter removed. So we are using the same driver between tests:
For additional comparison data I've shown the ES-290 biradial with the same RCF compression driver:"
Considering the 35cm depth it's respectable, but the loading characteristics are certainly not in the same ballpark as the Yuichi, let alone the Oris horn.
600 Hz seems to be the lowest usable frequency.
But this should come as no surprise.
Specification
- Horn mouth 85cm x 85cm (with mouth flares)
- Horn mouth 58cm x 58cm (without flares)
- Cutoff Frequency 300Hz (Fc)
- Coverage 90 degrees.
" The idea is to provide a large format oblate spheroidal horn flare which is characterized as a conical horn with a smooth throat transition.
Design Goals
- Easy to construct for DIY enthusiasts
- Horn throat can be 3D printed
- Horn petals are easy to construct especially compared to the Sabourin horn which consists of three flare segments. This Oblate Spheroidal (OS) consists of a single horn flare segment.
- The horn mouth flares are optional (see test data to compare with and without mouth flare pieces)
- Suitable for home theater, home hifi, and PA applications
- Provides constant directivity for use in PA
- Attempts low coloration sound
- Most Constant Directivity (CD) horns have high coloration due to abrupt physical horn flare geometry
- Provide reasonable falling response
- Most CD horns have significant falling response requiring EQ to flatten. This raises distortion in the treble region since the driver is having to work hard to reproduce those frequencies compared to an exponential horn flare.
By moving the mic away to 1m, removing the gate, and applying some smoothing,
we get a better sense on what happens near the cutoff frequency of the horn:
Response at 0,15,30, & 45 degrees off-axis:
Below is the response of the Yuichi A290 with the RCF ND940/950.
Please note that the ND940 is simply the ND950 with the conical adapter removed. So we are using the same driver between tests:
For additional comparison data I've shown the ES-290 biradial with the same RCF compression driver:"
Considering the 35cm depth it's respectable, but the loading characteristics are certainly not in the same ballpark as the Yuichi, let alone the Oris horn.
600 Hz seems to be the lowest usable frequency.
But this should come as no surprise.
Troy's own conclusion:
"While the horn sounded dynamic, intelligible, and coherent, it lacked the last little bit of clarity I've come to expect. This limitation reduced overall soundstage depth and smoothness, having some mild horn coloration. As a result the 2710 horn is perfectly suitable for PA applications or for home theater applications where dynamics and intelligibly are of primary concern. I would not use the 2710 horn in two channel music applications."
"This limitation reduced overall soundstage depth and smoothness, having some mild horn coloration."
For comparison (and fwiw), here's a review of a loudspeaker system that uses the same spherical horn (post #69), by one of the most renowned DIY-ers in Germany.
For comparison (and fwiw), here's a review of a loudspeaker system that uses the same spherical horn (post #69), by one of the most renowned DIY-ers in Germany.
"The first thing that strikes you is the excellent imaging ability of the speakers."
and:
"The timbres are spot on, with not a trace of the typical horn coloration."
and:
"The timbres are spot on, with not a trace of the typical horn coloration."
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The Western Electric 555W is generally considered the first high frequency compression driver, it used a 3.3" (84mm) dome diaphragm with a phase plug using four annular rings in 1926.
Most HF compression drivers still use very similar phase plug designs.
About 29 years later, JBL released the annular diaphragm ("ring radiator") 075 "bullet tweeter" in 1955, 70 years ago.
The tiny annular diaphragms of the 075 (or 2402, 2404, 2405 etc.) could "get by" with a single annular ring phase plug/horn.
Larger annular ring diaphragms with diaphragm area (Sd) approaching a 3" or 4" dome diaphragm may use two annular rings in the as in the BMS4592:
or three annular rings in the more recent Celestion Axi2050:
Anyway, the "30% more modern by age" annular diaphragms do have the advantage of requiring less of a span for the diaphragm material, but require two suspensions rather than one for a dome.
As usual, there are trade-offs in every design choice.
Art
Axiperioic is an exercise in FEM and not a useful driver.
Dual 3" JBL driver effectively has a larger 6" VC at a fraction of cost and weight. I watched the presentation Dr. Brown did about how he designed the Axi and he wasn't even trying to hide the fact it was not much more than his PHD thesis ( about modeling diaphragm modes ) turned into a driver, and he all but stated that the driver was useless except maybe for cinema speakers.
Yeah it's impressive as a science experiment but not useful. Like a 2012 Tesla Model S - showed the future but objectively wasn't a great car.
BMS is an actually useful driver, while also being extremely innovative when it came out, though it was a longer time ago. BMS is based on understanding of physics rather than on mathematical modeling like Axi.
and the RCF dome that i linked uses cutting edge metamaterial diaphragm in an otherwise pedestrian, century old driver design. i think it would be brilliant with a supertweeter because it is ruler flat to about 8 khz where the supertweeter can take over.
Dual 3" JBL driver effectively has a larger 6" VC at a fraction of cost and weight. I watched the presentation Dr. Brown did about how he designed the Axi and he wasn't even trying to hide the fact it was not much more than his PHD thesis ( about modeling diaphragm modes ) turned into a driver, and he all but stated that the driver was useless except maybe for cinema speakers.
Yeah it's impressive as a science experiment but not useful. Like a 2012 Tesla Model S - showed the future but objectively wasn't a great car.
BMS is an actually useful driver, while also being extremely innovative when it came out, though it was a longer time ago. BMS is based on understanding of physics rather than on mathematical modeling like Axi.
and the RCF dome that i linked uses cutting edge metamaterial diaphragm in an otherwise pedestrian, century old driver design. i think it would be brilliant with a supertweeter because it is ruler flat to about 8 khz where the supertweeter can take over.
Here's the response of the same horn (in red, unsmoothed) with the Western-Electric 594A.
It's a midrange driver by modern standards, but with some minor tweaks it was possible to reach 13-15 kHz.
It's a midrange driver by modern standards, but with some minor tweaks it was possible to reach 13-15 kHz.
OK, so you haven't tried it. That's all you needed to say.
No. The directivity is going to give out at a higher frequency with the classic horn, below which there's cutoff to steer clear of.
Tbh 'm not fond of annular diaphragms in general - this applies to tweeters and compression drivers.
Inner workings of the 4592ND:
The channels in the B&C DCX354 seem to be optimized:
Tried what? A naked compression driver without horn/waveguide?
B&C DE75/82 behind a sheet of plywood with a slightly reworked (exit) hole. Works fine from 800 Hz with just a protection cap at low output levels, but the driver obviously sounds (and works) better with a horn.
As for directivity in HF, I don't care about (hardly inevitable) increasing directivity, as long as it happens gradually/smoothly.
I don't think horn speakers are useful for near field listening, except in Camplo's specific case.
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BMS uses 45 degree high frequency mirrors that reflect HF at 90 degree angles.
B&C just tries to bend sound but sound is a wave not a metal rod. It doesn't bend - it reflects.
JBL has got it right with D2 in my opinion. But they just wire both voice coils in parallel ( or is it series ? ) They should have made it with a crossover like the others.
compression drivers are limited in the very high frequencies ( above 10 khz ) so the small supertweeter is a problem. JBL D2 has 3" on both coils and both are basically wide band supertweeters - which is the better design.
it's what i was talking about. the trend is to move from compression drivers with deep horns trying to reproduces low frequencies to basically giant supertweeters like D2.
prosound is all about arrays and arrays have a high frequency roll off due to phase issues, additionally air absorbs high frequencies over distances found in venues so in practice compression driver goal is to produce as much of very high frequency output as possible and midrange output is relegated to paper cones to allow designers to fully optimize compression drivers for VHF.
using compression drivers for midrange is pointless. there are many prosound paper midranges in 8" and 10" sizes with over 100db efficiency BEFORE any horn loading.
by asking a compression driver to do the job of a midrange you are inevitably compromising its VHF performance either by using a wider diaphragm or deeper horn. even a coaxial design like BMS or B&C is still a compromise.
use a D2 with a paper midrange !
It is a push-push (cancellation) design, which can be connected in parallel or series:
- Series VC: 104 db on the M2 horn
- Parallel VC: 110 db on M2 horn.
It's an advanced driver, albeit very expensive, quite fragile and almost impossible to repair.
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